Put Node Groups into Premade Categories
The simplest way to do it is using a python script.

First thing to do is to changing your node group name to have a '.' at the start, i.e: myXptoNodeGroup &gt;&gt; .myXptoNodeGroup. This way, the nodegroup will no longer appear in the &quot;Group&quot; menu.
The second thing to do is editing the following script by adding your nodegroup(s) to the items list of the ShaderNodeCategory instead of '.myXptoNodeGroup', and run the script:
import bpy
from nodeitems_utils import register_node_categories, unregister_node_categories, NodeItem
from nodeitems_builtins import ShaderNodeCategory

node_categories = [
    ShaderNodeCategory('SOMENODES', &quot;Some Nodes&quot;, items=[
        NodeItem('ShaderNodeGroup', &quot;myXptoNodeGroup&quot;, {&quot;node_tree&quot;: &quot;bpy.data.node_groups['.myXptoNodeGroup']&quot;} ),
    ]),
]

def register():
    register_node_categories('MYGROUPNODES', node_categories)


def unregister():
    unregister_node_categories('MYGROUPNODES')


if __name__ == &quot;__main__&quot;:
    register()

Of course, this is not exclusive to ShaderNodeGroups, it's just a matter to change the corresponding NodeCategory, and the NodeGroup type for the NodeItem.